This is a note to let you know that I've just added the patch titled power: supply: max17040: fix null-ptr-deref in max17040_probe() to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: power-supply-max17040-fix-null-ptr-deref-in-max17040.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit b7aaebfa23ada7d7045a42fbca8fbddf8070c1d5 Author: Yang Yingliang <yangyingliang@xxxxxxxxxx> Date: Fri Oct 8 14:31:50 2021 +0800 power: supply: max17040: fix null-ptr-deref in max17040_probe() [ Upstream commit 1d422ecfc48ee683ae1ccc9217764f6310c0ffce ] Add check the return value of devm_regmap_init_i2c(), otherwise later access may cause null-ptr-deref as follows: KASAN: null-ptr-deref in range [0x0000000000000360-0x0000000000000367] RIP: 0010:regmap_read+0x33/0x170 Call Trace: max17040_probe+0x61b/0xff0 [max17040_battery] ? write_comp_data+0x2a/0x90 ? max17040_set_property+0x1d0/0x1d0 [max17040_battery] ? tracer_hardirqs_on+0x33/0x520 ? __sanitizer_cov_trace_pc+0x1d/0x50 ? _raw_spin_unlock_irqrestore+0x4b/0x60 ? trace_hardirqs_on+0x63/0x2d0 ? write_comp_data+0x2a/0x90 ? __sanitizer_cov_trace_pc+0x1d/0x50 ? max17040_set_property+0x1d0/0x1d0 [max17040_battery] i2c_device_probe+0xa31/0xbe0 Fixes: 6455a8a84bdf ("power: supply: max17040: Use regmap i2c") Reported-by: Hulk Robot <hulkci@xxxxxxxxxx> Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxxxxx> Signed-off-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/power/supply/max17040_battery.c b/drivers/power/supply/max17040_battery.c index d956c67d51558..b6b29ec3d93ec 100644 --- a/drivers/power/supply/max17040_battery.c +++ b/drivers/power/supply/max17040_battery.c @@ -482,6 +482,8 @@ static int max17040_probe(struct i2c_client *client, chip->client = client; chip->regmap = devm_regmap_init_i2c(client, &max17040_regmap); chip->pdata = client->dev.platform_data; + if (IS_ERR(chip->regmap)) + return PTR_ERR(chip->regmap); chip_id = (enum chip_id) id->driver_data; if (client->dev.of_node) { ret = max17040_get_of_data(chip);